Speed regulating or controlling device for elevators.



Patented Oct. 24, |899.

E. P. FORBES. SPEED REGULATING 0R C'ONTROLLING DEVICE FOB ELEVATURS.

(Application led Feb. 20, 1899.)

UNITED STATES Price.

ArtNr EDWARD P. FORBES, OF HARTFORD, CONNECTICUT.

SPECIFICATION forming part of Letters Patent No. 635,679, dated October24, 1899.

Application tiled February 20, 1899. Serial No. 706,096. (No model.)

To @ZZ whom it may concern:

Be it known that I, EDWARD P. FORBES, 'a citizen of the United States,residing in Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in SpeedRegulating or Controlling Devices for Elevators, of which the followingis a specification.

This invention relates to means for regulating the speed and forcontrolling the movement of elevators, and has for its object to providedevices of the class mentioned whereby the speed of the elevator may beautomatically controlled, and also has for its object the automaticrelease of the speed-controlling devices in case the hoisting-ropeshould break or when from other causes the descent of the elevator isbeyond the control of the attendant.

In the accompanying drawings, Figure l represents a side view of theelevator and the controlling apparatus in its normal condition. Fig. 2represents a partial front view of the same. Fig. 3 is a viewcorresponding to Fig. l, showing the hoisting-rope broken and thecontrolling device in full operation; and Fig. 4 represents a detail tobe more fully described hereinafter.

Similar characters designate like parts in all the figures of thedrawings.

In the accompanying drawings, C represents the elevator-car; R, thehoisting-rope; r, the rope attached to the counterweight, and l0 what Ipreferably term the speedcontrolling rope, which, however, in this caseis entirely independent of either of the two ropes previously mentioned,but moves in unison therewith and is for thisreason attached to thecross-bar 1l at the top of the car C.

Located within or near the elevator-shaft is the tube or cylinder 12,the inside of which is smooth and is adapted to receive the piston P,provided with two heads 13 and 14, the former of which is directlyconnected with the cross-bar 11 by means of a rope 10, while the rope15, passing under the sheave 16, connects the head 14 of said piston Pwith the under side of the car C. Hence it will be understood that thepiston P is directly operated from the car C, but acts in opposition tothe movement of the same. In other words, when the car is ascending thepiston is descending within its tube, and the reverse is true during thedownward movement of said car.

The tube or cylinder l2 is rmly held in place by the bracket 17 at thetop of said tube and by a bracket I8 at the bottom thereof and carriesat its upper end a sleeve 20, held in sliding contact thereon andpreferably provided with a screw-thread 21, said sleeve being adaptedwhen released to slide downward on said tube l2 and to then cover aseries of openings 22 at the upper end of said tube when it is arrestedin its downward movement by the projecting ring 23 on said tube 12. Thesleeve 2O is supported in its normal position bya detent or hook lever24, which is pivoted at 25 to the bracket 1'7 and the lower end 24a ofwhich engages the screwthread. 2l, the object of which is to providemeans for adjusting the sleeve 2O vertically, so as to regulate the sizeof the openings 22 to any desired degree when in normal condition. Thelever 24 has an extension 24b beyond the pivot-point 25, which extensionis adapted to be operated to withdraw the hook 24 from the sleeve 2Owhen the speed of the descending elevator is beyond a predeterminedlimit or in case of accident-as, for instance, if the hoisting-ropeshould break-in which condition the ear will of course be beyond thecontrol of the operator. The rope l0 is carried over a pulley 30 and isconnected to the upper head 13 of the piston P, and it will therefore beseen that when the car C descends the pulley 30 will be rotated ordriven by the rope l0. At one side of said pulley I have provided aseries of pawls 3l, each of which is pivoted thereto, as at 32, and hasan extension 33, between which and the hub of the wheel a spring 34 isplaced, tending to throw the latch 3l toward the center of thepulley-shaft 35, and the springs 34 are so adjustedthat when thecircumferential speed. of the pulley 30 exceeds a certain limit thepawls 3l will be centrifugally thrown outward against the stress of saidsprings into such position that they will strike the extension 24b ofthe hook-lever 24, and thus cause the release of the sleeve 20, whichlatter will immediately drop and close the openings 22, thereby sealingthe upper end of said tube 12, so that as the car C descends the aircon- IOO tained in said tube between the piston-head 13 and thenow-sealed upper end thereot will be compressed to form a cushion, theettectiveness of which increases with the descent of the car and theconsequent ascent of the piston. At the lower end of the tube 12 Iprovide a similar sleeve 40, having a screwthread 41 and adapted toclose the openings 42 in the lower end of the cylinder 12. Anotherhook-lever 43 is pivoted at 44 to the tube 12, and the hook 43 thereofis adapted to engage the screw-thread 41, whereby the openings 42 may intheir normal or open condition be covered to anydesired extent. Thelever`43 is provided with the ear 43", which is connected, by means of arod, cord, or other device 45, to the ear 24C of the lever 24 abovementioned, so as to cause both levers 24 and 43 to be operatedsimultaneously for releasing their respective sleeves 40 and 20. It willtherefore be evident that when the sleeve 40 has closed the openings 42in the tube or cylinder 12 and the car descends a partial vacuum will beformed in the lower end of said tube between the piston-head 14 and thebracket 18, the effect of such vacuum increasing with the descent of thecar.

In order to close the ends of the cylinder 12 at the points where theropes 10 and 15 are passing through the heads or brackets 17 and 18, Ipreferably employ at these points the construction shown in Fig. 4, inwhich the cylinder 12 is represented as having a screw-thread 12Lengaging a corresponding screw-thread 17u on the bracket 17, so that thecylinder andthe brackets 17 and 1S form, practically, one solidstructure, and at the point where the ropes are passing through saidheads I prefer to employ a bushing B, having the head b at one end and anut n at the other end thereof, which bushing is provided with anopening to receive the rope 10 in a running but not loose fit, while thebody of the bushing B is somewhat smaller than the openingin the bracket17, so thatsaid bushing may adapt itself to the sway of the rope 10, andthereby prevent the latter from wearing' an enlargement in the head,which would naturally leave an opening for the air to escape. The rope15 passes through a similar bushing B', which prevents any undue leakageof air at the'lower end of the cylinder.

As the primary object of thesleeves 2O and 40 is to provide meanswhereby the passage of air into or out ot the cylinder l2 may beregulated, it is obvious that the smaller the openings 22 42 the moredifficult will be the movement of the piston P. In other words, in thiscondition the cylinder 12 performs the function of a dash-pot, whichpermits the piston to move only at a predetermined speed, such speedbeing dependent upon the facility with which the air can be forced outfrom one end and drawn into the other end of said cylind er. A secondaryobject of the sleeves 2O and 40 is to provide means whereby the ends ofthe cylinder 12 may be entirely closed to prevent the passage of aireither in or out of said cylinder at the time when the car is beyond thecontrol of the operator, so that an absolute air-cushion is formed atone end, while at the lower end the suction-openings are closed, and avacuum will naturally result by the upward movement of the piston I.

YVhen the car is beyond the control of the attendant, as abovementioned, I deem it a matter of great importance that the power of thedriving mechanism should be instantly shut ott or disconnected, and Itherefore provide means whereby such power is automatically disconnectedfrom said driving mechanism at the moment when the sleeves 2O and 40 arereleased, as above described.

` In the accompanying drawings I have illustrated a switch S, throughwhich when arranged as shown in Fig. 1 an electric current will pass tothe motor for driving the hoisting mechanism, and the switch-leverlisconnected, by means of the pitman l', to the end of the hook-lever 43,so thatwhen said hooklever 43 is thrown out of engagement with thesleeve 40 the switch-arm Z is thrown into the position shown in Fig. 3and will consequen tly break the current at that point, leaving themotor disconnected. Instead of being connected to the switch-lever Z therod Z may be attached to a belt-shipper or to the stem o't` a valve ofWhatever system may be used for operating the elevator.

It is to benoted that the tube or cylinder 12 constitutes an air-chamberand that it is immaterial how such chamber may be formed. So, too, thesleeves 2O and 40 constitute valves for regulating the ent-rance of airto and its exit from the chamber, and, as is obvious, the form of thesevalves may be varied within wide limits without departing from myinvention. Furthermore, said valves need not necessarily be externallythreaded, as illustrated and described, as other provisions couldreadily be adopted for engaging the latches or hook-levers 24 and 43.Many of the details of the mechanism described could also be modifiedand still be within the purview of the invention.

The elevator m ay be of any well-known type and may be operated byany-motor common to the art.

Having described my invention, I claim- 1. The combination, with anelevator, of an air-cham ber adjacent thereto; a piston in saidairchamber connected at different points to the elevator-car; andautomatic means, governed by the movement of the car, for regulating thepassage of air into and from said air-chamber.

2. The combination, with an elevator, of an air-chamber adjacent theretoand provided with passages to permit the entrance and exit of air, of apiston in said air-chamber connected at different points with theelevatorcar; and means, governed by the movement of the car, forcontrolling the action of said piston.

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3. The combination, with an elevator, of a cylinder adjacent thereto,said cylinder having air entrance and exit openin gs at its ends; apiston mounted within said cylinder and connected at each respective endwith the elevator-car; valves for controlling the size of the airentrance and exit openings; and means, governed by the movement of thecar, for automatically releasing said valves should the elevator exceeda predetermined speed.

4. In combination with an elevator, an airchamber having air exit andentrance openings at its ends; valves for governing the entrance of airinto, and its exit from, said openings; means for holding said valves intheir desired positions; and means, governed by the movement of theelevator-car, for automatically releasing said valves.

5. The combination, with an elevator, of an air-chamber adjacent theretoprovided with air entrance and exit openings; sleeve-valves forregulating the size of said openings; means for holding said valves intheir desired positions; means for releasing said valves; and meanswithin the air-chamber for controlling the movement of the elevator-car.

6. The combination, with an elevator, of an air-chamber adjacentthereto; a piston 4connected with the elevator and freely movable insaid air-chamber; valves for regulating the supply of air to, and itsexit from, said airchamber,said valves being provided with projections;latches for engaging said projections and holding the valves in theirdesired positions; and means, governed by the movement of the car, fortripping said latches.

7. In combination with an elevator, a cylindrical tube havingair-passages at its upper and lower ends; externally-threadedsleevevalves for regulating the size of said passages; a piston withinsaid tube connected at both ends with the elevator-car; pulleys overwhich the connections pass; and a centrifugal device, carried by one ofthe pulleys, for releasing the latches holding the sleeve-valves.

8. In an elevator, the combination,with an elevator-car, of acylindrical tube having airpassagcs at its upper and lower ends;externallythreaded sleeve -valves for governing the size of saidpassages; a double-headed piston Within said tubes; connections passingfrom the upper and lower heads orn said piston, respectively, to theupper and lower ends of the elevator-car; latches for holding thesleeve-valves in their desired positions; a connection between saidlatches; and a series of centrifugally-operated devices, controlled bythe mechanism of the car, for tripping one of said latches.

9. In combination,with an elevator, an airchamber adjacent thereto andprovided with air entrance and outlet openings; adjustable valves forcontrolling said openings; means for holding said valves in their adjusted positions; a piston within the air-chamber, said piston beingconnected to the car; and means, operated by the car when it exceeds apredetermined limit of speed, for releasing said valves.

l0. The combination,with an elevator, of an air-chamber adjacent thereto`provided with air inlet and exit openings; a piston within theair-chamber; connections from said piston to the car; valves forcontrolling the entrance of air to, and its ex'it from, said openings;means for holding said valves in their desired positions; means,governed by the car when it exceeds a predetermined limit of speed, forreleasing said valves; and means for shutting oft' the power for drivingthe elevator when said valves are released.

ll. The combination,with an elevator, of an air-chamber adjacent theretoprovided with air inlet and outlet openings; a piston in saidair-chamber connected to the car adjustable valves for regulating thesize of said openings; means for holding said valves in their adj ustedpositions; means, governed by the speed of the elevator,for releasingsaid valves and aconnection from one of said means to the source ofpower. f

12. The combin ation ,with an elevator,oiI an air-chamber adjacentthereto, said chamber being provided with air inlet and exit openings atits lower and upper ends, respectively; adjustable valves forcontrolling the size of said openings; means for holding said valves intheir adjusted positions; a piston within the air-chamber, said pistonbeing connected at each end with the elevator-car; and means forreleasing the valves, one of said means involving a device for shuttingoff the power. 13. The combination, with an elevator, of a cylindricalair-chamber contiguous thereto and provided `with air inlet and outletopenings at its ends; valves for controlling the size of said openings;a piston within the air-chamber and connected by ropes with each end ofthe elevator; pulleys over which said ropes pass; and a device, carriedby the tube, for permitting slight movement of one of the ropes, toprevent leakage of air or the enlargement of the space within which therope opcrates.

. EDWARD P. FORBES. Witnesses:

WM. I-I. BLODGETT, HENRY BrssnLL.

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